Now you've really got me obsessed Adam. Time for some more detective work...
Looking at a few photos of Lou - he's holding a glass in his RIGHT hand in one, but he's holding his coat, slung over his shoulder, with his LEFT in another. But unfortunately a third picture shows him holding a cigarette with his right hand. So nothing decisive there, but a two-to-one probability that we are wrong.
Perhaps he's ambidextrous. Or maybe the eight weeks of electric shock treatment he received aged seventeen - at the desperate request of his parents to cure him of homosexuality and playing the electric guitar - handicapped him in a similarly ambiguous way as left-handedness limits/enhances other guitarists' axe lucidity. Now there's food for thought...